1. Field of the Invention
This invention relates to a high-density, integrated circuit module, which includes a plurality of stacked individual integrated circuit devices including complex geometric or serpentine interconnect rails for selectively interconnecting leads of the stacked integrated circuit devices to each other and to external circuitry.
2. Discussion of the Related Technology
One method of achieving an ultra high density integrated circuit module, which includes stacked individual integrated circuit devices, is to use external electrical interconnect rails to interconnect electrical leads extending from the stacked individual integrated circuit devices within the module. This method and high density module is described in U.S. Pat. Nos. 5,279,029 and 5,367,766, which are assigned to the common assignee of the present invention and are incorporated by reference herein for all purposes.
In applications where the high density integrated circuit module includes dissimilar integrated circuit devices, e.g. memory devices, microprocessor, DMA device, etc., or where the lead-to-lead spacing of individual devices is not uniform, there is a need for a signal path that provides selectable electrical interconnections between the dissimilar integrated circuit devices which make up the module.
Although the prior art discloses a method and apparatus for electrically interconnecting the leads of stacked integrated circuit devices within a high density module, the electrical interconnect rails associated with these prior art devices are linear, which makes electrical interconnection with leads of every other device in the stack, or with every third or fourth device in the stack, more difficult. Leads from integrated circuit devices which are not to be electrically connected to the linear rails must be trimmed internally or externally so as to not contact the rail or, at the very least, bent away from the rails so that the solder connection between the rails and the leads is simply not made. This requires a more complex manufacturing process.
The need exists for a rail design which enables complex electrical interconnections with leads of selected integrated circuit devices within the high density module, without requiring leads to be trimmed, which simplifies the module manufacturing process.